Read this op-ed in the Washington Post. If it doesn’t being tears to your eyes, you have no heart.
Here is the salient part:

And I’ve learned that war most often claims the lives of young kids who go out on patrol day after day, night after night. They go because they are good soldiers led by good sergeants. They go with a singular purpose: to not let their buddies down. Each soldier we lay to rest shared that goal. They kept faith with their comrades, even in the face of danger and death. That is the most humbling lesson of all.